简算13又 1/5*5/6+28又 2/7*7/9

问题描述:

简算13又 1/5*5/6+28又 2/7*7/9
.....

13又 1/5*5/6+28又 2/7*7/9
=(12+6/5 )x5/6+(27+9/7)x7/9
=10+1+21+1
=33